A USB storage medium, that can use required data anytime or anywhere, is a representative portable storage device. The USB storage medium is easy to carry and to use, and therefore, is widely used for storing files.
Since anyone may easily read and write the data in a USB storage medium in the related art, there is a risk that important data may be leaked. Therefore, although a USB storage medium enhanced with security functions has been launched, the launched USB storage medium has functions only blocking usage access of specific persons or has a problem that it is difficult to perfectly protect information from attacks such as a volume DUMP of hackers.